- 1. Having been a babysitter, an older brother, and a primary teacher, I've seen that little girls are just as likely as little boys to initiate a fight (the boys are more likely to win, but they both initiate with about equal frequency).
2. Having been through the public school system:- a. Guys tend to be more accepting of others while girls are more clique-ish. This behavior on a global scale would lead to less, not more, diplomacy
b. Guys are more likely to fight at this stage, but when girls fight it's a lot scarier. Guys punch and maybe kick. With girls, it's no holds barred—scratching, biting, hair pulling, &c. I once saw two fighting girls rip a drinking fountain off the wall.
- a. Guys tend to be more accepting of others while girls are more clique-ish. This behavior on a global scale would lead to less, not more, diplomacy
I assume that most or all women serving in major leadership positions would be post-menopausal, so I'll skip the clichés about monthly menstrual moodiness since they wouldn't really apply.
Also, Hugh Nibley, in his Women's Conference talk "Patriarchy and Matriarchy" suggests that a "matriarchal" society tends towards luxurious and licentious behavior (so in that sense you could argue that the U.S. is already trending towards matriarchy). Italics are mine:
Babylon (which Brother Nibley identifies as matriarchal in spite of its being ruled by a king) certainly wasn't pacifist. On a side note, the book/movie Fight Club explores the idea that Western culture is tending towards more violence and sexuality because so many men today were raised by single mothers. Make of it what you will.The matriarchal cultures are sedentary (remember that the mother stays home either as Penelope or as the princess confined in the tower), that is, agricultural, chthonian, centering around the Earth Mother. The rites are mostly nocturnal, lunar, voluptuous, and licentious. The classic image is that of the great, rich, corrupt, age-old, and oppressive city Babylon, queen of the world, metropolis, fashion center, the super mall, the scarlet woman, the whore of all the earth, whose merchants and bankers are the oppressors of all people. Though the matriarchy makes for softness and decay, beneath the gentle or beguiling or glittering exterior is the fierce toughness, cunning, and ambition of Miss Piggy, Becky Sharp, or Scarlett O'Hara.
Now, to do justice, Brother Nibley also has some harsh criticism for patriarchal societies:
This duality of matriarchy vs. patriarchy is at the heart of many of societies ills. Because they are constantly pitted against each other, as Brother Nibley says, we end up with the worst of both, swinging back and forth in a cycle similar to the Nephite pride cycle. Instead, the true pattern for ruling and societal culture is the blending of both male and female impulses. In the Church, this pattern is known as the Patriarchal Order of the Priesthood. Don't let the name throw you. There's not a focus on maintaining men in power; there's a focus on the family—men and women ruling together (1 Corinthians 11:11).The patriarchal order lends itself to equally impressive abuses. It is nomadic. The hero is the wandering Odysseus or knight errant, the miles gloriosus, the pirate, condottiere, the free enterpriser—not the farmer tied to wife and soil, but the hunter and soldier out for adventure, glory, and loot; not the city, but the golden horde, the feralis exercitus that sweeps down upon the soft and sedentary cultures of the coast and the river valley. Its gods are sky gods with the raging sun at their head. Its depradations are not by decay but by fire and sword. As predatory and greedy as the matriarchy, it cumulates its wealth not by unquestioned immemorial custom but by sacred and self-serving laws. The perennial routine calls for the patriarchal tribes of the mountains and the steppes to overrun the wealthy and corrupt cities of the plain only to be absorbed and corrupted by them in turn, so that what we end up with in the long run is the worst of both cultures.
So with women in all the major world leadership positions, we might have less war, but other things would get worse. The best system (which seems to be what we're headed towards) is one where men and women share power.